Treatment of oral candidiasis with methylene blue-mediated photodynamic therapy in an immunodeficient murine model.

Abstract

OBJECTIVES:

The purpose of this study was to evaluate the efficacy of using methylene blue (MB)-mediated photodynamic therapy to treat oral candidiasis in an immunosuppressed murine model, mimicking what is found in human patients.

STUDY DESIGN:

Seventy-five experimental mice with severe combined immunodeficiency disease were inoculated orally with Candida albicans by swab 3 times a week for a 4-week period. On treatment day, mice were cultured for baseline fungal growth and received a topical oral cavity administration of 0.05 mL MB solution at one of the following concentrations: 250, 275, 300, 350, 400, 450, or 500 microgram/mL. After 10 minutes the mice were recultured and underwent light activation with 664 nm of diode laser light with a cylindrical diffuser. After photodynamic therapy the mice were cultured again for colony-forming units per milliliter and then killed, their tissue harvested for histopathology.

RESULTS AND CONCLUSIONS:

The results indicate an MB dose-dependent effect. Concentrations from 250 to 400 microgram/mL reduced fungal growth but did not eliminate Candida albicans. MB concentrations of 450 and 500 microgram/mL totally eradicated Candida albicans from the oral cavity, resulting in reductions from 2.5 log(10) and 2.74 log(10) to 0, respectively. These results suggest that MB-mediated photodynamic therapy can potentially be used to treat oral candidiasis in immunodeficient patients.

• Authors: M C Teichert, J W Jones, M N Usacheva, M A Biel
• Journal: Oral surgery, oral medicine, oral pathology, oral radiology, and endodontics (Oral Surg Oral Med Oral Pathol Oral Radiol Endod) Vol. 93 Issue 2 Pg. 155-60 (Feb 2002) ISSN: 1079-2104 [Print] United States
• PMID: 11862203 (Publication Type: Evaluation Study, Journal Article, Research Support, U.S. Gov't, P.H.S.)

Chemical References

• Antifungal Agents
• Azoles
• Photosensitizing Agents
• Methylene Blue

Topics

• Animals
• Antifungal Agents (pharmacology)
• Azoles (pharmacology)
• Candida albicans (drug effects)
• Candidiasis, Oral (drug therapy, microbiology)
• Colony Count, Microbial
• Disease Models, Animal
• Dose-Response Relationship, Drug
• Drug Resistance, Fungal
• Methylene Blue (administration & dosage, therapeutic use)
• Mice
• Mice, Nude
• Mice, SCID
• Photochemotherapy (methods)
• Photosensitizing Agents (administration & dosage, therapeutic use)